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Pecquet AM, Bridgwood K, Cowie D, Hofstra A, Wu Y, Whalley S, Webb SD. Data derived extrapolation factors (DDEFs) for rat to human interspecies extrapolation for the HPPD inhibitor mesotrione. Crit Rev Toxicol 2024; 54:418-429. [PMID: 38869005 DOI: 10.1080/10408444.2024.2353174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/04/2024] [Indexed: 06/14/2024]
Abstract
In the risk assessment of agrochemicals, there has been a historical paucity of using data to refine the default adjustment factors, even though large datasets are available to support this. The current state of the science for addressing uncertainty regarding animal to human extrapolation (AFA) is to develop a "data-derived" adjustment factor (DDEF) to quantify such differences, if data are available. Toxicokinetic (TK) and toxicodynamic (TD) differences between species can be utilized for the DDEF, with human datasets being ideal yet rare. We identified a case for a currently registered herbicide, mesotrione, in which human TK and TD are available. This case study outlines an approach for the development of DDEFs using comparative human and animal data and based on an adverse outcome pathway (AOP) for inhibition of 4-hydroxyphenol pyruvate dioxygenase (HHPD). The calculated DDEF for rat to human extrapolation (AFA) for kinetics (AFAK = 2.5) was multiplied by the AFA for dynamics (AFAD = 0.3) resulting in a composite DDEF of ∼1 (AFA = 0.75). This reflects the AOP and available scientific evidence that humans are less sensitive than rats to the effects of HPPD inhibitors. Further analyses were conducted utilizing in vitro datasets from hepatocytes and liver cytosols and extrapolated to whole animal using in vitro to in vivo extrapolation (IVIVE) to support toxicodynamic extrapolation. The in vitro datasets resulted in the same AFAD as derived for in vivo data (AFAD = 0.3). These analyses demonstrate that a majority of the species differences are related to toxicodynamics. Future work with additional in vitro/in vivo datasets for other HPPD inhibitors and cell types will further support this result. This work demonstrates utilization of all available toxicokinetic and toxicodynamic data to replace default uncertainty factors for agrochemical human health risk assessment.
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Affiliation(s)
- Alison M Pecquet
- Product Safety, Syngenta Crop Protection LLC, Greensboro, NC, USA
| | - Katy Bridgwood
- Syngenta Jealott's Hill International Research Centre, Bracknell, UK
| | - David Cowie
- Syngenta Jealott's Hill International Research Centre, Bracknell, UK
| | | | - Yaoxing Wu
- Product Safety, Syngenta Crop Protection LLC, Greensboro, NC, USA
| | - Sarah Whalley
- Syngenta Jealott's Hill International Research Centre, Bracknell, UK
| | - Steven D Webb
- Syngenta Jealott's Hill International Research Centre, Bracknell, UK
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Silva MAP, Figueiredo DBS, de Carvalho LR, Braz LG, Braz MG. Modulation of gene expression and influence of gene polymorphisms related to genotoxicity and redox status on occupational exposure to inhaled anesthetics. Int J Hyg Environ Health 2024; 256:114307. [PMID: 38065035 DOI: 10.1016/j.ijheh.2023.114307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/19/2023]
Abstract
The extensive use of inhalational anesthetics contributes to both indoor and outdoor (environmental) pollution. The influence of genetic susceptibility on DNA damage and oxidative stress and the possible modulation of gene expression have not yet been investigated upon occupational exposure to waste anesthetic gases (WAGs). This study assessed 8-oxoguanine DNA glycosylase 1 (OGG1) and superoxide dismutase 2 (SOD2) gene expression, which are related to oxidized DNA repair and antioxidant capacity, respectively, and the influence of their polymorphisms (OGG1 rs1052133 and SOD2 rs4880) in 100 professionals highly exposed to WAGs and 93 unexposed volunteers (control group). Additionally, X-ray repair cross complementing 1 (XRCC1 rs25487 and rs1799782) and ataxia telangiectasia mutated (ATM rs600931) gene polymorphisms as well as genetic instability (micronucleus-MN and nuclear bud-NBUD) and oxidative stress (malondialdehyde-MDA and ferric reducing antioxidant power-FRAP) biomarkers were assessed in the groups (control and exposed) and in the subgroups of the exposed group according to job occupation (anesthesiologists versus surgeons/technicians). Except for the ATM TT controls (associated with increased FRAP), there were no influences of OGG1, XRCC1, ATM, and SOD2 polymorphisms on MN, NBUD, MDA, and FRAP values in exposed or control subjects. No significant difference in the expression of either gene evaluated (OGG1 and SOD2) was found between the exposed and control groups. Increased OGG1 expression was observed among OGG1 -/Cys individuals only in the control group. Among the exposed group, anesthesiologists had a greater duration of WAG exposure (both h/week and years) than surgeons/technicians, which was associated with increased MDA and decreased antioxidant capacity (FRAP) and SOD2 expression (redox status). Higher expression of OGG1 was found in -/Cys surgeons/technicians than in anesthesiologists with the same genotype. Increased antioxidant capacity was noted in the surgeons/technicians carrying the ATM T allele and in those carrying XRCC1 -/Gln. Increased MN was influenced by OGG1 -/Cys in surgeons/technicians. Anesthesiologists with ATM CC exhibited increased MN, and those carrying the C allele (CC/CT genotype) exhibited increased NBUD. SOD2 polymorphism did not seem to be relevant for WAG exposure. These findings contribute to advancing the knowledge on genetic susceptibility/gene expression/genetic instability/oxidative stress, including differences in job occupation considering the workload, in response to occupational exposure to WAGs.
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Affiliation(s)
- Mariane A P Silva
- GENOTOX Laboratory, Medical School, Sao Paulo State University - UNESP, Botucatu, Brazil
| | - Drielle B S Figueiredo
- GENOTOX Laboratory, Medical School, Sao Paulo State University - UNESP, Botucatu, Brazil
| | - Lídia R de Carvalho
- Institute of Biosciences, Sao Paulo State University - UNESP, Botucatu, Brazil
| | - Leandro G Braz
- GENOTOX Laboratory, Medical School, Sao Paulo State University - UNESP, Botucatu, Brazil
| | - Mariana G Braz
- GENOTOX Laboratory, Medical School, Sao Paulo State University - UNESP, Botucatu, Brazil.
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Kostirko D, Zhao J, Lavigne M, Hermant B, Totten L. A rapid review of best practices in the development of risk registers for public health emergency management. Front Public Health 2023; 11:1200438. [PMID: 38098833 PMCID: PMC10720617 DOI: 10.3389/fpubh.2023.1200438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023] Open
Abstract
Introduction Public health organizations (PHO) must prepare to respond to a range of emergencies. This represents an ongoing challenge in an increasingly connected world, where the scope, complexity, and diversity of public health threats (PHT) have expanded, as exemplified by the COVID-19 pandemic. Risk registers (RR) offer a framework for identifying and managing threats, which can be employed by PHOs to better identify and characterize health threats. The aim of this review is to establish best practices (BP) for the development of RRs within Public Health Emergency Management (PHEM). Methods In partnership with a librarian from Health Canada (HC), and guided by the Cochrane Rapid Review Guideline, journal articles were retrieved through MEDLINE, and a comprehensive search strategy was applied to obtain grey literature through various databases. Articles were limited to those that met the following criteria: published on or after January 1, 2010, published in the English language and published within an Organisation for Economic Co-operation and Development setting. Results 57 articles were included for synthesis. 41 papers specifically discussed the design of RRs. The review identified several guidelines to establish RRs in PHEM, including forward-looking, multidisciplinary, transparent, fit-for-purpose, and utilizing a systems approach to analyze and prioritize threats. Expert consultations, literature reviews, and prioritization methods such as multi-criteria-decision-analysis (MCDA) are often used to support the development of RRs. A minimum five-year-outlook is applied to assess PHTs, which are revisited yearly, and iteratively revised as new knowledge arises. Discussion Based upon this review, RRs offer a systems approach to PHEM that can be expanded to facilitate the analysis of disparate threats. These approaches should factor in the multidimensionality of threats, need for multi-sectoral inputs, and use of vulnerability analyses that consider inherent drivers. Further research is needed to understand how drivers modify threats. The BPs and recommendations highlighted in our research can be adopted in the practice of PHEM to characterize the public health (PH) risk environment at a given point in time and support PHOs policy and decision-making.
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Affiliation(s)
- Danylo Kostirko
- Risk and Capability Assessment Unit, Public Health Agency of Canada, Ottawa, ON, Canada
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Hadrup N, Sahlgren N, Jacobsen NR, Saber AT, Hougaard KS, Vogel U, Jensen KA. Toxicity dose descriptors from animal inhalation studies of 13 nanomaterials and their bulk and ionic counterparts and variation with primary particle characteristics. Nanotoxicology 2023:1-34. [PMID: 37300873 DOI: 10.1080/17435390.2023.2221728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 05/28/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023]
Abstract
This study collects toxicity data from animal inhalation studies of some nanomaterials and their bulk and ionic counterparts. To allow potential grouping and interpretations, we retrieved the primary physicochemical and exposure data to the extent possible for each of the materials. Reviewed materials are compounds (mainly elements, oxides and salts) of carbon (carbon black, carbon nanotubes, and graphene), silver, cerium, cobalt, copper, iron, nickel, silicium (amorphous silica and quartz), titanium (titanium dioxide), and zinc (chemical symbols: Ag, C, Ce, Co, Cu, Fe, Ni, Si, Ti, TiO2, and Zn). Collected endpoints are: a) pulmonary inflammation, measured as neutrophils in bronchoalveolar lavage (BAL) fluid at 0-24 hours after last exposure; and b) genotoxicity/carcinogenicity. We present the dose descriptors no-observed-adverse-effect concentrations (NOAECs) and lowest-observed-adverse-effect concentrations (LOAECs) for 88 nanomaterial investigations in data-library and graph formats. We also calculate 'the value where 25% of exposed animals develop tumors' (T25) for carcinogenicity studies. We describe how the data may be used for hazard assessment of the materials using carbon black as an example. The collected data also enable hazard comparison between different materials. An important observation for poorly soluble particles is that the NOAEC for neutrophil numbers in general lies around 1 to 2 mg/m3. We further discuss why some materials' dose descriptors deviate from this level, likely reflecting the effects of the ionic form and effects of the fiber-shape. Finally, we discuss that long-term studies, in general, provide the lowest dose descriptors, and dose descriptors are positively correlated with particle size for near-spherical materials.
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Affiliation(s)
- Niels Hadrup
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
- Research group for risk-benefit, National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Nicklas Sahlgren
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
| | - Nicklas R Jacobsen
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
| | - Anne T Saber
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
| | - Karin S Hougaard
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Ulla Vogel
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
- National Food Institute, Technical University of Denmark, Lyngby, Denmark
| | - Keld A Jensen
- National Research Centre for the Working Environment (NFA), Copenhagen, Denmark
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Integrating toxicokinetics into toxicology studies and the human health risk assessment process for chemicals: Reduced uncertainty, better health protection. Regul Toxicol Pharmacol 2021; 128:105092. [PMID: 34863906 DOI: 10.1016/j.yrtph.2021.105092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 11/23/2021] [Accepted: 11/29/2021] [Indexed: 01/16/2023]
Abstract
The database of practical examples where toxicokinetic (TK) data has benefitted all stages of the human health risk assessment process are increasingly being published and accepted. This review aimed to highlight and summarise notable examples and to describe the "state of the art" in this field. The overall recommendation is that for any in vivo animal study conducted, measurements of TK should be very carefully considered for inclusion as the numerous benefits this brings continues to grow, particularly during the current march towards animal free toxicology testing and ambitions to eventually conduct human health risk assessments entirely based upon non-animal methods.
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Yang Y, Filipovic D, Bhattacharya S. A Negative Feedback Loop and Transcription Factor Cooperation Regulate Zonal Gene Induction by 2, 3, 7, 8-Tetrachlorodibenzo-p-Dioxin in the Mouse Liver. Hepatol Commun 2021; 6:750-764. [PMID: 34726355 PMCID: PMC8948569 DOI: 10.1002/hep4.1848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 10/02/2021] [Accepted: 10/10/2021] [Indexed: 01/04/2023] Open
Abstract
The cytochrome P450 (Cyp) proteins Cyp1A1 and Cyp1A2 are strongly induced in the mouse liver by the potent environmental toxicant 2, 3, 7, 8‐tetrachlorodibenzo‐p‐dioxin (TCDD), acting through the aryl hydrocarbon receptor (AHR). The induction of Cyp1A1 is localized within the centrilobular regions of the mouse liver at low doses of TCDD, progressing to pan‐lobular induction at higher doses. Even without chemical perturbation, metabolic functions and associated genes are basally zonated in the liver lobule along the central‐to‐portal axis. To investigate the mechanistic basis of spatially restricted gene induction by TCDD, we have developed a multiscale computational model of the mouse liver lobule with single‐cell resolution. The spatial location of individual hepatocytes in the model was calibrated from previously published high‐resolution images. A systems biology model of the network of biochemical signaling pathways underlying Cyp1A1 and Cyp1A2 induction was then incorporated into each hepatocyte in the model. Model simulations showed that a negative feedback loop formed by binding of the induced Cyp1A2 protein to TCDD, together with cooperative gene induction by the β‐catenin/AHR/TCDD transcription factor complex and β‐catenin, help produce the spatially localized induction pattern of Cyp1A1. Although endogenous WNT regulates the metabolic zonation of many genes, it was not a driver of zonal Cyp1A1 induction in our model. Conclusion: In this work, we used data‐driven computational modeling to identify the mechanistic basis of zonally restricted gene expression induced by the potent and persistent environmental pollutant TCDD. The multiscale model and derived results clarify the mechanisms of dose‐dependent hepatic gene induction responses to TCDD. Additionally, this work contributes to our broader understanding of spatial gene regulation along the liver lobule.
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Affiliation(s)
- Yongliang Yang
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA.,Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, USA
| | - David Filipovic
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA.,Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, USA.,Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, USA
| | - Sudin Bhattacharya
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA.,Institute for Quantitative Health Science & Engineering, Michigan State University, East Lansing, MI, USA.,Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA.,Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
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Klapacz J, Gollapudi BB. Considerations for the Use of Mutation as a Regulatory Endpoint in Risk Assessment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:84-93. [PMID: 31301246 DOI: 10.1002/em.22318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Assessment of a chemical's potential to cause permanent changes in the genetic code has been a common practice in the industry and regulatory settings for decades. Furthermore, the genetic toxicity battery of tests has typically been employed during the earliest stages of the research and development programs of new product development. A positive outcome from such battery has a major impact on the chemical's utility, industrial hygiene, product stewardship practices, and product life cycle analysis, among many other decisions that need to be taken by the industry, even before the registration of a chemical is undertaken. Under the prevailing regulatory paradigm, the dichotomous (yes/no) evaluation of the chemical's genotoxic potential leads to a conservative, linear no-threshold (LNT) risk assessment, unless compelling and undeniable data to the contrary can be provided to satisfy regulators, typically in a number of different global jurisdictions. With the current advent of predictive methods, new testing paradigms, mode-of-action/adverse outcome pathways, and quantitative risk assessment approaches, various stakeholders are starting to employ these state-of-the-science methodologies to further the conversation on decision making and advance the regulatory paradigm beyond the dominant LNT status quo. This commentary describes these novel methodologies, relevant biological responses, and how these can affect internal and regulatory risk assessment approaches. Environ. Mol. Mutagen. 61:84-93, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Joanna Klapacz
- Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, Michigan
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Heflich RH, Johnson GE, Zeller A, Marchetti F, Douglas GR, Witt KL, Gollapudi BB, White PA. Mutation as a Toxicological Endpoint for Regulatory Decision-Making. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:34-41. [PMID: 31600846 DOI: 10.1002/em.22338] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 09/09/2019] [Accepted: 09/14/2019] [Indexed: 05/23/2023]
Abstract
Mutations induced in somatic cells and germ cells are responsible for a variety of human diseases, and mutation per se has been considered an adverse health concern since the early part of the 20th Century. Although in vitro and in vivo somatic cell mutation data are most commonly used by regulatory agencies for hazard identification, that is, determining whether or not a substance is a potential mutagen and carcinogen, quantitative mutagenicity dose-response data are being used increasingly for risk assessments. Efforts are currently underway to both improve the measurement of mutations and to refine the computational methods used for evaluating mutation data. We recommend continuing the development of these approaches with the objective of establishing consensus regarding the value of including the quantitative analysis of mutation per se as a required endpoint for comprehensive assessments of toxicological risk. Environ. Mol. Mutagen. 61:34-41, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Robert H Heflich
- U.S. Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas
| | | | - Andreas Zeller
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Canada
| | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Canada
| | - Kristine L Witt
- National Institutes of Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | | | - Paul A White
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Canada
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Davis A, Javernick-Will A, Cook SM. Analyzing Sanitation Sustainability Assessment Frameworks for Resource-Limited Communities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13535-13545. [PMID: 31674173 DOI: 10.1021/acs.est.9b03134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Diverse and numerous sanitation sustainability assessment frameworks have been created to enhance the ability of systems to provide safe sanitation services, especially in resource-limited contexts. However, many go unused while new frameworks are developed and high sanitation system failure rates persist. To better support the sustainable development goal around global sanitation, there is a need to better understand how sanitation sustainability is defined and measured and the potential advantages and disadvantages of existing assessment frameworks. A subset of existing sanitation sustainability assessment frameworks was reviewed after applying each to evaluate multiple successful and failed community sanitation systems in India. Overall, the evaluated frameworks did not share a sanitation sustainability definition or core set of essential indicators. Many indicators lacked clear definitions and guidance on data collection and analysis. When evaluating framework effectiveness, differentiations between successful and failed cases varied greatly between frameworks. Potential improvements include indicator pilot testing to verify measurement feasibility and that they provide expected results; context-specific weightings; and project-specific framework selection. Clarifying and improving sanitation sustainability assessment frameworks could increase their effectiveness and use, leading to better decision-making and improved public and environmental health, economic viability, and sanitation use and acceptance.
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Affiliation(s)
- Allie Davis
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Amy Javernick-Will
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Sherri M Cook
- Department of Civil, Environmental, and Architectural Engineering , University of Colorado Boulder , Boulder , Colorado 80309 , United States
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Nonanimal toxicology testing approaches for traditional and deemed tobacco products in a complex regulatory environment: Limitations, possibilities, and future directions. Toxicol In Vitro 2019; 62:104684. [PMID: 31618670 DOI: 10.1016/j.tiv.2019.104684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 11/20/2022]
Abstract
The evaluation of tobacco products is complex due to a multitude of factors including product diversity, limited testing standards, and variability in user behavior. Alternative approaches in current testing paradigms have limitations that generally truncate their applicability beyond screening for hazard identification; this is also true for toxicological evaluations of tobacco products. In a regulatory context, results from tobacco product toxicity assessments are extrapolated to the in vivo condition to assess human health relevance at the individual and population level. A key limitation of alternative approaches is the difficulty and uncertainty in extrapolating results to adverse outcomes relevant to chronic tobacco exposures in humans. This difficulty and uncertainty are increased when comparing toxicological outcomes between tobacco products. Given that the interpretation and quantification of differences in assay results (e.g., mutagenicity) for tobacco product comparison may be inconclusive, the predictive value of these approaches for human risk of relevant downstream pathologies (e.g., carcinogenesis) can be limited. Development and validation of fit-for-purpose alternative approaches that are predictive of human toxicity and dose response assays with adequate sensitivity and specificity for product comparisons would help advance the field of predictive toxicology.
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Kahl VFS, Simon D, de Souza MR, da Rosa VH, Nicolau C, Da Silva FR, Kvitko K, Peres A, Dorneles GP, de Souza CT, Dias JF, Da Silva J. Base excision repair (OGG1 and XRCC1) and metabolism (PON1) gene polymorphisms act on modulation of DNA damage and immune parameters in tobacco farmers. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 836:9-18. [PMID: 30442351 DOI: 10.1016/j.mrgentox.2018.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 04/03/2018] [Accepted: 04/03/2018] [Indexed: 12/12/2022]
Abstract
Pesticides are one of the most frequently investigated chemical, due to their multiple uses in agricultural and public health areas. This study evaluates lymphocytes CBMN (cytokinesis-block micronucleus cytome assay), inflammatory markers, inorganic elements in blood samples, and the relationship of these parameters with XRCC1Arg194Trp, OGG1Ser326Cys and PON1Gln192Arg polymorphisms in a population of tobacco farmers. The study population comprised 129 agricultural workers exposed to pesticides and 91 nonexposed. Farmers had significantly increased NPB (nuclear plasmatic bridge), MN (micronucleus) and NBUD (nuclear bud) frequencies, as well as IL-6 (interleukin 6) and TNF-α (tumor necrosis factor alpha) serum levels, and decreased cytokines CD4+/CD8+ ratio. In the exposed group, XRCC1 Trp/- was correlated with decreased NDI (nuclear division index), and OGG1 Cys/- was associated with higher levels of NPB and decreased levels of IL-6. The combined effects of PON1 Arg/- and XRCC1 Arg/Arg were associated with increased NPB frequencies. In addition, the combination of PON1 Arg/- with XRCC1 Trp/- or OGG1 Cys/- influenced in increased levels of necrosis in farmers. Furthermore, tobacco farmers showed a positive correlation between TNF-α levels and NPB, CD4+/CD8+ ratio and NBUD; and IL-6 levels with both MN and NDI. The duration of years of work at tobacco fields was correlated positively with NBUD frequency. Sulfur, chlorine and potassium were found at increased levels in the exposed group when compared to the nonexposed one. These findings provide evidence that tobacco farmers' exposure have increased DNA damage and alter the immune system's response, and that XRCC1 and OGG1 polymorphisms could influence both biomarkers results.
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Affiliation(s)
- Vivian Francilia Silva Kahl
- Laboratory of Toxicological Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 4th floor, Canoas, Brazil.
| | - Daniel Simon
- Laboratory of Human Molecular Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 5th floor, Canoas, Brazil
| | - Melissa Rosa de Souza
- Laboratory of Toxicological Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 4th floor, Canoas, Brazil
| | - Vieira Henrico da Rosa
- Laboratory of Toxicological Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 4th floor, Canoas, Brazil
| | - Caroline Nicolau
- Laboratory of Toxicological Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 4th floor, Canoas, Brazil
| | - Fernanda R Da Silva
- Postgraduate Program in Environmental Impact Assessment, UniLaSalle, Av. Victor Barreto, 2288, Canoas, Brazil
| | - Katia Kvitko
- Postgraduate Program in Genetics and Molecular Biology (PPGGBM), Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, building 43323, Porto Alegre, Brazil
| | - Alessandra Peres
- Cellular and Molecular Immunology Laboratory, Federal University of Health Sciences of Porto Alegre, Rua Sarmento Leite, 245, Porto Alegre, Brazil; Research Center, Methodist University Center IPA, R. Dona Leonor, 340, Porto Alegre, Brazil
| | - Gilson Pires Dorneles
- Cellular and Molecular Immunology Laboratory, Federal University of Health Sciences of Porto Alegre, Rua Sarmento Leite, 245, Porto Alegre, Brazil
| | - Cláudia Telles de Souza
- Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, Brazil; Laboratory of Environmental Chemistry and Oleochemistry, Postgraduate Program in Chemistry, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, Brazil
| | - Johnny Ferraz Dias
- Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, Brazil
| | - Juliana Da Silva
- Laboratory of Toxicological Genetics, Postgraduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, building 22, 4th floor, Canoas, Brazil.
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Kahl VFS, da Silva FR, Alves JDS, da Silva GF, Picinini J, Dhillon VS, Fenech M, de Souza MR, Dias JF, de Souza CT, Salvador M, Branco CDS, Thiesen FV, Simon D, da Silva J. Role of PON1, SOD2, OGG1, XRCC1, and XRCC4 polymorphisms on modulation of DNA damage in workers occupationally exposed to pesticides. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 159:164-171. [PMID: 29747151 DOI: 10.1016/j.ecoenv.2018.04.052] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/21/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
Tobacco farming has been proving to induce poor health outcomes in agricultural workers, genomic instability being the triggering one. This study evaluated influence of PON1 (paraoxonase 1), SOD2 (superoxide dismutase), OGG1 (8-oxoguanine glycosylase), XRCC1 (X-ray repair cross-complementing protein 1), and XRCC4 (X-ray repair cross-complementing protein 4) genes polymorphisms on DNA damage in 121 subjects occupationally exposed to pesticides mixtures and nicotine at tobacco fields and 121 non-exposed individuals. Inorganic elements (Cl, P, S and Zn) and cotinine levels were found increased in farmers, confirming exposure. Results show higher frequencies of buccal micronucleus (MN), nuclear buds (NBUD), binucleated cells (BN) and damage index (comet assay), reduced telomere length (TL), and increased parameters of oxidative stress in farmers compared to non-exposed individuals. PON1 Gln/Gln genotype was associated with increased MN frequency. SOD2 Val/Val showed association with increased frequency of MN and NBUD and decreased antioxidant activity. The XRCC1 Arg/Arg showed protective effect for MN, BN and TL, which was also positively influenced by OGG1 -/Cys. MN was decreased in XRCC4 -/Ile farmers. These genotypes also showed a risk for antioxidant activity. Our study proposes that PON1 and SOD2 variants play a role in xenobiotic-metabolizing system in farmers, while base excision repair (BER) pathway could be the repair mechanism involved in genomic instability suffered by tobacco farmers.
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Affiliation(s)
- Vivian F Silva Kahl
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | | | - Jodel da Silva Alves
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | - Gabrieli Flesch da Silva
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | - Juliana Picinini
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | - Varinderpal Singh Dhillon
- Health and Biosecurity Flagship, Commonwealth Scientific and Industrial Research Organization (CSIRO), Adelaide, SA, Australia
| | - Michael Fenech
- Health and Biosecurity Flagship, Commonwealth Scientific and Industrial Research Organization (CSIRO), Adelaide, SA, Australia
| | - Melissa Rosa de Souza
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | - Johnny F Dias
- Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Claudia Telles de Souza
- Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mirian Salvador
- Biotechnology Institute, University of Caxias do Sul, Caxias do Sul, RS, Brazil
| | | | - Flávia Valadão Thiesen
- Toxicology Institute, Catholic Pontifice University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Daniel Simon
- Laboratory of Human Molecular Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
| | - Juliana da Silva
- Laboratory of Toxicological Genetics, Post-Graduate Program in Cellular and Molecular Biology Applied to Health (PPGBioSaúde), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil
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15
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Becker RA, Dreier DA, Manibusan MK, Cox LAT, Simon TW, Bus JS. How well can carcinogenicity be predicted by high throughput "characteristics of carcinogens" mechanistic data? Regul Toxicol Pharmacol 2017; 90:185-196. [PMID: 28866267 DOI: 10.1016/j.yrtph.2017.08.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 11/16/2022]
Abstract
IARC has begun using ToxCast/Tox21 data in efforts to represent key characteristics of carcinogens to organize and weigh mechanistic evidence in cancer hazard determinations and this implicit inference approach also is being considered by USEPA. To determine how well ToxCast/Tox21 data can explicitly predict cancer hazard, this approach was evaluated with statistical analyses and machine learning prediction algorithms. Substances USEPA previously classified as having cancer hazard potential were designated as positives and substances not posing a carcinogenic hazard were designated as negatives. Then ToxCast/Tox21 data were analyzed both with and without adjusting for the cytotoxicity burst effect commonly observed in such assays. Using the same assignments as IARC of ToxCast/Tox21 assays to the seven key characteristics of carcinogens, the ability to predict cancer hazard for each key characteristic, alone or in combination, was found to be no better than chance. Hence, we have little scientific confidence in IARC's inference models derived from current ToxCast/Tox21 assays for key characteristics to predict cancer. This finding supports the need for a more rigorous mode-of-action pathway-based framework to organize, evaluate, and integrate mechanistic evidence with animal toxicity, epidemiological investigations, and knowledge of exposure and dosimetry to evaluate potential carcinogenic hazards and risks to humans.
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Affiliation(s)
- Richard A Becker
- American Chemistry Council, 700 Second St., NE, Washington DC 20002, USA.
| | - David A Dreier
- Center for Environmental & Human Toxicology, University of Florida, Gainesville, FL, USA
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16
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Becker RA, Dellarco V, Seed J, Kronenberg JM, Meek B, Foreman J, Palermo C, Kirman C, Linkov I, Schoeny R, Dourson M, Pottenger LH, Manibusan MK. Quantitative weight of evidence to assess confidence in potential modes of action. Regul Toxicol Pharmacol 2017; 86:205-220. [DOI: 10.1016/j.yrtph.2017.02.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/17/2017] [Accepted: 02/18/2017] [Indexed: 12/31/2022]
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17
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Rees BJ, Tate M, Lynch AM, Thornton CA, Jenkins GJ, Walmsley RM, Johnson GE. Development of an in vitro PIG-A gene mutation assay in human cells. Mutagenesis 2017; 32:283-297. [PMID: 28057708 PMCID: PMC5907909 DOI: 10.1093/mutage/gew059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/15/2016] [Indexed: 11/12/2022] Open
Abstract
Mutagens can be carcinogens, and traditionally, they have been identified in vitro using the Salmonella 'Ames' reverse mutation assay. However, prokaryotic DNA packaging, replication and repair systems are mechanistically very different to those in the humans we inevitably seek to protect. Therefore, for many years, mammalian cell line genotoxicity assays that can detect eukaryotic mutagens as well as clastogens and aneugens have been used. The apparent lack of specificity in these largely rodent systems, due partly to their mutant p53 status, has contributed to the use of animal studies to resolve data conflicts. Recently, silencing mutations at the PIG-A locus have been demonstrated to prevent glycophosphatidylinositol (GPI) anchor synthesis and consequentially result in loss of GPI-anchored proteins from the cell's extracellular surface. The successful exploitation of this mutant phenotype in animal studies has triggered interest in the development of an analogous in vitro PIG-A mutation screening assay. This article describes the development of a robust assay design using metabolically active human cells. The assay includes viability and cell membrane integrity assessment and conforms to the future ideas of the 21st-century toxicology testing.
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Affiliation(s)
- Benjamin J Rees
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Matthew Tate
- Gentronix Ltd BioHub at Alderley Park, Alderley Edge, Cheshire, UK
| | | | - Catherine A Thornton
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Gareth J Jenkins
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
| | - Richard M Walmsley
- Gentronix Ltd BioHub at Alderley Park, Alderley Edge, Cheshire, UK
- Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - George E Johnson
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, UK
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18
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Dourson ML, Gadagbui BK, Thompson RB, Pfau EJ, Lowe J. Managing risks of noncancer health effects at hazardous waste sites: A case study using the Reference Concentration (RfC) of trichloroethylene (TCE). Regul Toxicol Pharmacol 2016; 80:125-33. [DOI: 10.1016/j.yrtph.2016.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/03/2016] [Accepted: 06/14/2016] [Indexed: 11/29/2022]
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19
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Simon TW, Zhu Y, Dourson ML, Beck NB. Bayesian methods for uncertainty factor application for derivation of reference values. Regul Toxicol Pharmacol 2016; 80:9-24. [DOI: 10.1016/j.yrtph.2016.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/03/2016] [Accepted: 05/16/2016] [Indexed: 12/17/2022]
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20
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Dourson ML, York RG. Advances in assessing ingredient safety. Regul Toxicol Pharmacol 2016; 79 Suppl 2:S112-8. [PMID: 27427210 DOI: 10.1016/j.yrtph.2016.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 10/21/2022]
Abstract
The safety of food ingredients will be assessed in the 21st century by mixture of traditional methods, such as the "safe" dose concept, which is thought to be an accurate but imprecise estimation of dose below the population threshold for adverse effect, and contemporary methods, such as the Benchmark Dose (BMD), Chemical Specific Adjustment Factors (CSAF), physiologically-based pharmacokinetic models, and biologically-informed dose response modeling. New research on the horizon related to toxicology 21 may also improve these risk assessment methods, or suggest new ones. These traditional, contemporary and new methods and research will be briefly described.
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Affiliation(s)
- Michael L Dourson
- Toxicology Excellence for Risk Assessment (TERA), 2300 Montana Avenue, Suite 409, Cincinnati, OH 45211, USA.
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21
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Trans fatty acids and cholesterol levels: An evidence map of the available science. Food Chem Toxicol 2016; 98:269-281. [PMID: 27394654 DOI: 10.1016/j.fct.2016.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 07/01/2016] [Accepted: 07/04/2016] [Indexed: 01/01/2023]
Abstract
High intakes of industrial trans fatty acids (iTFA) increase circulating low density lipoprotein cholesterol (LDL-C) levels, which has implicated iTFA in coronary heart disease (CHD) risk. Published data on iTFA and LDL-C, however, represent higher intake levels than the U.S. population currently consume. This study used state-of-the-art evidence mapping approaches to characterize the full body of literature on LDL-C and iTFA at low intake levels. A total of 32 independent clinical trials that included at least one intervention or control group with iTFA at ≤3%en were found. Findings indicated that a wide range of oils and interventions were used, limiting the ability to determine an isolated effect of iTFA intake. Few data points were found for iTFA at <3%en, with the majority of low-level exposures actually representing control group interventions containing non-partially hydrogenated (PHO) oils. Further, it appears that few dose-response data points are available to assess the relationship of low levels of iTFA, particularly from PHO exposure, and LDL-C. Therefore, limited evidence is available to determine the effect of iTFA at current consumption levels on CHD risk.
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22
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Beck NB, Becker RA, Erraguntla N, Farland WH, Grant RL, Gray G, Kirman C, LaKind JS, Jeffrey Lewis R, Nance P, Pottenger LH, Santos SL, Shirley S, Simon T, Dourson ML. Approaches for describing and communicating overall uncertainty in toxicity characterizations: U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) as a case study. ENVIRONMENT INTERNATIONAL 2016; 89-90:110-128. [PMID: 26827183 DOI: 10.1016/j.envint.2015.12.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 12/22/2015] [Accepted: 12/24/2015] [Indexed: 06/05/2023]
Abstract
Single point estimates of human health hazard/toxicity values such as a reference dose (RfD) are generally used in chemical hazard and risk assessment programs for assessing potential risks associated with site- or use-specific exposures. The resulting point estimates are often used by risk managers for regulatory decision-making, including standard setting, determination of emission controls, and mitigation of exposures to chemical substances. Risk managers, as well as stakeholders (interested and affected parties), often have limited information regarding assumptions and uncertainty factors in numerical estimates of both hazards and risks. Further, the use of different approaches for addressing uncertainty, which vary in transparency, can lead to a lack of confidence in the scientific underpinning of regulatory decision-making. The overarching goal of this paper, which was developed from an invited participant workshop, is to offer five approaches for presenting toxicity values in a transparent manner in order to improve the understanding, consideration, and informed use of uncertainty by risk assessors, risk managers, and stakeholders. The five approaches for improving the presentation and communication of uncertainty are described using U.S. Environmental Protection Agency's (EPA's) Integrated Risk Information System (IRIS) as a case study. These approaches will ensure transparency in the documentation, development, and use of toxicity values at EPA, the Agency for Toxic Substances and Disease Registry (ATSDR), and other similar assessment programs in the public and private sector. Further empirical testing will help to inform the approaches that will work best for specific audiences and situations.
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Affiliation(s)
- Nancy B Beck
- American Chemistry Council, 700 2nd St NE, Washington, DC 20002, United States.
| | - Richard A Becker
- American Chemistry Council, 700 2nd St NE, Washington, DC 20002, United States.
| | - Neeraja Erraguntla
- Texas Commission on Environmental Quality, PO Box 13087, Austin, TX 78711, United States.
| | - William H Farland
- Colorado State University, 135 Physiology (1680 Campus Delivery), Fort Collins, CO 80523, United States.
| | - Roberta L Grant
- Texas Commission on Environmental Quality, PO Box 13087, Austin, TX 78711, United States.
| | - George Gray
- Milken Institute School of Public Health, George Washington University,950 New Hampshire Ave, NW, Washington, DC 20051, United States.
| | - Christopher Kirman
- Summit Toxicology LLP, 29449 Pike Drive, Orange Village, OH 44022, United States.
| | - Judy S LaKind
- LaKind Associates, LLC; Department of Epidemiology and Public Health, University of Maryland School of Medicine, Milton S. Hershey Medical Center, 106 Oakdale Ave. Catonsville, MD 21228, United States; Department of Pediatrics, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, 106 Oakdale Ave., Catonsville, MD 21228, United States.
| | - R Jeffrey Lewis
- ExxonMobil Biomedical Sciences, 1545 US Highway 22 East, Annandale, NJ 08801, United States.
| | - Patricia Nance
- Toxicology Excellence for Risk Assessment (TERA) Center, Department of Environmental Health College of Medicine, University of Cincinnati, 160 Panzeca Way, Kettering Laboratory, Room G24, Cincinnati, OH 45267, United States.
| | - Lynn H Pottenger
- The Dow Chemical Company, Toxicology and Environmental Research and Consulting, Midland, MI 48674, United States
| | - Susan L Santos
- FOCUS GROUP Risk Communication and Environmental Management Consultants, 29 Welgate Rd., Medford, MA 02155, United States.
| | - Stephanie Shirley
- Texas Commission on Environmental Quality, PO Box 13087, Austin, TX 78711, United States.
| | - Ted Simon
- Ted Simon LLC, 4184 Johnston Rd, Winston, GA 30187, United States.
| | - Michael L Dourson
- Toxicology Excellence for Risk Assessment (TERA) Center, Department of Environmental Health College of Medicine, University of Cincinnati, 160 Panzeca Way, Kettering Laboratory, Room G24, Cincinnati, OH 45267, United States.
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23
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Terry C, Hays S, McCoy AT, McFadden LG, Aggarwal M, Rasoulpour RJ, Juberg DR. Implementing a framework for integrating toxicokinetics into human health risk assessment for agrochemicals. Regul Toxicol Pharmacol 2016; 75:89-104. [DOI: 10.1016/j.yrtph.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 10/01/2015] [Accepted: 10/04/2015] [Indexed: 01/25/2023]
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24
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Azuma K, Uchiyama I, Uchiyama S, Kunugita N. Assessment of inhalation exposure to indoor air pollutants: Screening for health risks of multiple pollutants in Japanese dwellings. ENVIRONMENTAL RESEARCH 2016; 145:39-49. [PMID: 26618504 DOI: 10.1016/j.envres.2015.11.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 06/05/2023]
Abstract
Over the past few decades, multiple low level indoor pollutants have been found in domestic dwellings. The types and concentrations of these indoor pollutants have not been consistent over time and have changed with alterations in lifestyle, the development of novel products used in housing, and the development of new measurement technologies. To clarify the highest risk pollutants for which health risks should be reduced, we conducted a health risk assessment of 49 indoor air pollutants measured in 602 houses during winter and summer from 2012 to 2014. Inhalation reference concentrations were determined, and the margins of exposure were estimated for each indoor pollutant from measured indoor air concentrations. Health risks due to ammonia and acidic gases, including formic acid, acetic acid, and hydrogen chloride, were also assessed. Overall, during both winter and summer, the highest risk pollutants were acrolein, nitrogen dioxide, benzene, formic acid, and hydrogen chloride. The health risks of propanal, acetaldehyde, and 1,4-dichlorobenzene were also high. Principal component analysis (PCA) suggested an independent principal component for 1,4-dichlorobenzene. The primary source of exposure to 1,4-dichlorobenzene in Japan is an indoor household insect repellent. The improvement of individual lifestyle and housing may be appropriate targets for reducing the risk associated with this compound. The provision of further information on the risk to consumers and promotion of changes in consumer consciousness are needed. PCA suggested that the health risks of indoor air pollutants are amalgamated into similar chemical families, such as aldehydes, aliphatic hydrocarbons, aromatic hydrocarbons, or acetic esters. Our results suggest that health-based guidelines or source control measures, based on these chemical families and similar health endpoints, are appropriate for reducing total health risk due to multiple low level indoor pollutants.
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Affiliation(s)
- Kenichi Azuma
- Department of Environmental Medicine and Behavioral Science, Kinki University Faculty of Medicine, 377-2 Ohnohigashi, Osakasayama, Osaka 589-8511, Japan; Sick-house Medical Science Laboratory, Division of Basic Research, Louis Pasteur Center for Medical Research, 103-5, Tanakamonzen-cho, Sakyo-ku, Kyoto 606-8225, Japan.
| | - Iwao Uchiyama
- Sick-house Medical Science Laboratory, Division of Basic Research, Louis Pasteur Center for Medical Research, 103-5, Tanakamonzen-cho, Sakyo-ku, Kyoto 606-8225, Japan.
| | - Shigehisa Uchiyama
- Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako-shi, Saitama 351-0197, Japan.
| | - Naoki Kunugita
- Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako-shi, Saitama 351-0197, Japan.
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25
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Greenberg M, Goldstein BD, Anderson E, Dourson M, Landis W, North DW. Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2015; 35:1959-1968. [PMID: 26595455 DOI: 10.1111/risa.12535] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Six multi-decade-long members of SRA reflect on the 1983 Red Book in order to examine the evolving relationship between risk assessment and risk management; the diffusion of risk assessment practice to risk areas such as homeland security and transportation; the quality of chemical risk databases; challenges from other groups to elements at the core of risk assessment practice; and our collective efforts to communicate risk assessment to a diverse set of critical groups that do not understand risk, risk assessment, or many other risk-related issues. The authors reflect on the 10 recommendations in the Red Book and present several pressing challenges for risk assessment practitioners.
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Affiliation(s)
- Michael Greenberg
- EJ Bloustein School of Planning and Public Policy, Rutgers University, New Brunswick, NJ, USA
| | - Bernard D Goldstein
- University of Pittsburgh, Environmental and Occupational Health, Pittsburgh, PA, USA
| | | | | | - Wayne Landis
- Western Washington University, Institute for Environmental Toxicology, Bellingham, WA, USA
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26
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Aylward LL, Seiber JN, Hays SM. California biomonitoring data: Comparison to NHANES and interpretation in a risk assessment context. Regul Toxicol Pharmacol 2015; 73:875-84. [PMID: 26449396 DOI: 10.1016/j.yrtph.2015.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 09/11/2015] [Accepted: 10/01/2015] [Indexed: 11/24/2022]
Abstract
The California Environmental Biomonitoring Program (also known as Biomonitoring California) has been generating human biomonitoring data and releasing it via their website. The current Biomonitoring California program is a collection of smaller studies, targeting specific populations (e.g., fire fighters, breast cancer patients and controls, etc.). In this paper we compare the results from Biomonitoring California with those from the US National Health and Nutrition Examination Survey (NHANES). We also compare California's results with Biomonitoring Equivalents (BEs) for those compounds for which BEs exist. In general, the results from California are consistent with the biomonitoring levels found across the US via NHANES. A few notable exceptions are levels of flame retardants amongst fire fighters in California, which are higher than observed in NHANES and some persistent organic chemicals amongst a study of breast cancer patients and controls in California which are higher than in the overall adult population in NHANES. The higher levels amongst fire fighters may be a result of fire fighters being exposed to higher levels of flame retardants while fighting fires. The higher levels of the persistent organics amongst breast cancer patients is likely due to this population being older than the mean age in NHANES. Comparisons to BEs indicate that biomonitoring levels in California are all consistently below levels of concern as established by regulatory agencies.
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Affiliation(s)
- Lesa L Aylward
- Summit Toxicology, LLP, Falls Church, VA 22044, USA; National Centre for Environmental Toxicology, University of Queensland, Brisbane, QLD, Australia
| | - James N Seiber
- Department of Environmental Toxicology, University of California, Davis, CA 95616, USA
| | - Sean M Hays
- Summit Toxicology, LLP, Allenspark, CO 80510, USA.
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27
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Pastoor TP, Bachman AN, Bell DR, Cohen SM, Dellarco M, Dewhurst IC, Doe JE, Doerrer NG, Embry MR, Hines RN, Moretto A, Phillips RD, Rowlands JC, Tanir JY, Wolf DC, Boobis AR. A 21st century roadmap for human health risk assessment. Crit Rev Toxicol 2015; 44 Suppl 3:1-5. [PMID: 25070413 DOI: 10.3109/10408444.2014.931923] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The Health and Environmental Sciences Institute (HESI)-coordinated Risk Assessment in the 21st Century (RISK21) project was initiated to develop a scientific, transparent, and efficient approach to the evolving world of human health risk assessment, and involved over 120 participants from 12 countries, 15 government institutions, 20 universities, 2 non-governmental organizations, and 12 corporations. This paper provides a brief overview of the tiered RISK21 framework called the roadmap and risk visualization matrix, and articulates the core principles derived by RISK21 participants that guided its development. Subsequent papers describe the roadmap and matrix in greater detail. RISK21 principles include focusing on problem formulation, utilizing existing information, starting with exposure assessment (rather than toxicity), and using a tiered process for data development. Bringing estimates of exposure and toxicity together on a two-dimensional matrix provides a clear rendition of human safety and risk. The value of the roadmap is its capacity to chronicle the stepwise acquisition of scientific information and display it in a clear and concise fashion. Furthermore, the tiered approach and transparent display of information will contribute to greater efficiencies by calling for data only as needed (enough precision to make a decision), thus conserving animals and other resources.
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28
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Assessment of long-term health risks after accidental exposure using haemoglobin adducts of epichlorohydrin. Toxicol Lett 2014; 231:378-86. [DOI: 10.1016/j.toxlet.2014.07.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/24/2014] [Accepted: 07/16/2014] [Indexed: 11/21/2022]
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29
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Kohonen P, Ceder R, Smit I, Hongisto V, Myatt G, Hardy B, Spjuth O, Grafström R. Cancer biology, toxicology and alternative methods development go hand-in-hand. Basic Clin Pharmacol Toxicol 2014; 115:50-8. [PMID: 24779563 DOI: 10.1111/bcpt.12257] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/21/2014] [Indexed: 12/13/2022]
Abstract
Toxicological research faces the challenge of integrating knowledge from diverse fields and novel technological developments generally in the biological and medical sciences. We discuss herein the fact that the multiple facets of cancer research, including discovery related to mechanisms, treatment and diagnosis, overlap many up and coming interest areas in toxicology, including the need for improved methods and analysis tools. Common to both disciplines, in vitro and in silico methods serve as alternative investigation routes to animal studies. Knowledge on cancer development helps in understanding the relevance of chemical toxicity studies in cell models, and many bioinformatics-based cancer biomarker discovery tools are also applicable to computational toxicology. Robotics-aided, cell-based, high-throughput screening, microscale immunostaining techniques and gene expression profiling analyses are common tools in cancer research, and when sequentially combined, form a tiered approach to structured safety evaluation of thousands of environmental agents, novel chemicals or engineered nanomaterials. Comprehensive tumour data collections in databases have been translated into clinically useful data, and this concept serves as template for computer-driven evaluation of toxicity data into meaningful results. Future 'cancer research-inspired knowledge management' of toxicological data will aid the translation of basic discovery results and chemicals- and materials-testing data to information relevant to human health and environmental safety.
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Affiliation(s)
- Pekka Kohonen
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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Gonzalez-Suarez I, Sewer A, Walker P, Mathis C, Ellis S, Woodhouse H, Guedj E, Dulize R, Marescotti D, Acali S, Martin F, Ivanov NV, Hoeng J, Peitsch MC. Systems biology approach for evaluating the biological impact of environmental toxicants in vitro. Chem Res Toxicol 2014; 27:367-76. [PMID: 24428674 DOI: 10.1021/tx400405s] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exposure to cigarette smoke is a leading cause of lung diseases including chronic obstructive pulmonary disease and cancer. Cigarette smoke is a complex aerosol containing over 6000 chemicals and thus it is difficult to determine individual contributions to overall toxicity as well as the molecular mechanisms by which smoke constituents exert their effects. We selected three well-known harmful and potentially harmful constituents (HPHCs) in tobacco smoke, acrolein, formaldehyde and catechol, and established a high-content screening method using normal human bronchial epithelial cells, which are the first bronchial cells in contact with cigarette smoke. The impact of each HPHC was investigated using 13 indicators of cellular toxicity complemented with a microarray-based whole-transcriptome analysis followed by a computational approach leveraging mechanistic network models to identify and quantify perturbed molecular pathways. HPHCs were evaluated over a wide range of concentrations and at different exposure time points (4, 8, and 24 h). By high-content screening, the toxic effects of the three HPHCs could be observed only at the highest doses. Whole-genome transcriptomics unraveled toxicity mechanisms at lower doses and earlier time points. The most prevalent toxicity mechanisms observed were DNA damage/growth arrest, oxidative stress, mitochondrial stress, and apoptosis/necrosis. A combination of multiple toxicological end points with a systems-based impact assessment allows for a more robust scientific basis for the toxicological assessment of HPHCs, allowing insight into time- and dose-dependent molecular perturbations of specific biological pathways. This approach allowed us to establish an in vitro systems toxicology platform that can be applied to a broader selection of HPHCs and their mixtures and can serve more generally as the basis for testing the impact of other environmental toxicants on normal bronchial epithelial cells.
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Affiliation(s)
- Ignacio Gonzalez-Suarez
- Philip Morris International R&D, Philip Morris Products S.A. , Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland
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